1901.] NATURAL SCIENCES OF nilLADELPIIIA. 437 



adults iu their care of the offspring, or else wonderful tenacity of 

 life on the part of the young ants. 



The workers care for the pupfc with the same assiduity that dis- 

 tinguishes their attention to the eggs and the larvte, but this atten- 

 tion does not appear to be necessary to the survival of the pupa?. 

 I isolated ten pupaj in a Petri cell, having the same warmth, 

 moisture, and general environment as had those pupre remaining 

 under the care of the workers, and although half of them were 

 taken from their nurses before any color had been deposited in 

 their integuments, every one of them came safely to the adult- 

 stage. When, as callows, they were one by one returned to their 

 adult kin, they received such an extraordinary amount of licking 

 as to suggest the well-known theory that the pupre exude a sub- 

 stance which is liked by the ants, and that the attention of the 

 latter to the pupre is not wholly altruistic. 



These ants are very cleanly. In every nest where I have long 

 kept them they have chosen a fixed place for the throwing of re- 

 fuse, as remote as possible from the inert young. 



They carry morsels of food and lay them on the sponges, as if 

 with intent to moisten edibles that are too dry for their eating. 



They follow their usual occupations both by day and by night. 

 Individual ants rest sometimes for hours, standing motionless and 

 apparently asleep. I have seen a worker spend more than an 

 hour upon her toilet, combing or licking ever}' part of her body 

 as tar as she could reach. Much willing service is renderd by the 

 adults to each other in the cleaning of their integuments. I saw 

 one worker hold another by a foot, apparently insisting upon such 

 service, which was rendered at intervals and was renewed only 

 when a limb was again nipped, during forty minutes. On the final 

 release of the operator the two ants turned mouth to mouth and 

 one regurgitated food to the other. 



The muscular endurance of these ants seems to be great. They 

 will fight with no cessation during several hours, holding an enemy 

 by a limb or mandible. When the fight is a duel, the stronger ant, 

 or the ant that first succeeds in nipping a leg or an antenna, 

 thereby drags its opponent over objects, itself keeping the higher 

 ground, until the limb is severed. In the Lubbock nests, the 

 stronger fighter always threw the weaker into the moat, either 

 before or after the death of the unfortunate. AVhen a battleground 



